1. Field of the Invention
The invention relates to a process for producing Si—C-linked copolymers from organic polymers and organo-polysiloxanes.
2. Description of the Related Art
SiC-linked copolymers are typically formed from silicones and organic polymers by using essentially three processes: the reaction of silicone polymer such as polyether siloxanes with isocyanates (PU-silicones); the reaction of epoxysiloxanes with polyamines; and the hydrosilylation of allyloxy polymers. While the first two processes require specialty raw materials which are relatively costly, it is costly noble-metal catalysts which are needed in the last case.
U.S. Pat. No. 4,622,348 describes accelerators for free-radically polymerizable compositions obtained via a two-step reaction of chlorosulfonyl isocyanate, by first reacting the isocyanate group with an equivalent amount of a hydroxyl-containing compound and subsequently reacting the sulfonyl chloride group with an equivalent amount of a primary or secondary amine. The hydroxyl-containing compound may be, for example, propargyl alcohol which can be bound to a silicone by a hydrosilylation reaction, or the primary amine may be an aminosilane and a polymer may be obtained by a subsequent condensation polymerization or equilibration.
U.S. Pat. No. 5,189,217 describes a different reactivity pattern for chlorosulfonyl isocyanate in the background art. Chlorosulfonyl isocyanate (CSI) reacts with a methane-sulfonylmethylamine (MMSA) on the sulfone side at first to form a methanesulfonyl-N-methylaminosulfonyl isocyanate (MSMASI). The isocyanate group is then reacted with an amino compound, 2-amino-4,6-dimethoxy-pyrimidine, in a second step.